The long-term objective of this research is to gain better understanding of the neural mechanisms of perception and memory. It is designed to provide new knowledge concerning the processes by which the brain of the primate encodes, retains, and utilizes sensory information in behavior. The rationale is based on suggestive evidence that the posterior parietal cortex, in man and monkey, is the neural substrate for representation of information acquired by active touch (haptically). The work will be conducted on macaques (Macaca mulatta) trained to distinguish objects by touch and to remember their features for later recognition. Nerve-cell activity will be recorded from prefrontal and parietal cortex while the monkey is engaged in haptic performance. The functional interactions between parietal and prefrontal cortex will be explored with a combination of cryogenic and microelectrode recording methods in the behavioral setting. An important and innovative aspect of this research is the in-depth computational analysis of temporal patterns of neuron discharge during haptic discrimination and shorterm memory. Present knowledge of cortical organization raises the possibility that the firing patterns of cortical nerve cells reflect the patterns of reentry of impulses from other parts of the representational networks to which they belong. Thus, the effects of cooling one cortical region will be analyzed on the neuronal discharge patterns of another, as will be the effects of cortical cooling on behavioral performance. The aim is to clarify the functional interactions between components of cortical networks in sensory perception and short-term memory. The results of these experiments may help us elucidate the pathogenesis of disorders of the cerebral cortex in the human and to develop remedial measures for them.